Congrats on your first 1/2 marathon! You shouldn't have any problems jumping right into the NTP training program. The runs are pretty short right now, and the biking and swimming will actually be really good for your recovery. Just listen to how your body is feeling and go from there.

welcome to NTP. The half-marathon will give you a great base for your tri training. The most interesting adjustment (if you are anything like me) will be spending more time on the bike and less on the pavement but over time, I came to be amazed at how my running endurance was enhanced by my time in the saddle without the impact of running.

But agree with sandy - recovery is key and then you'll have a great base for all of your zone 2 training!